The present invention relates to a new type of paint product, namely, a solid paint having dimensional stability based on ion bonding.
Various resin compositions consisting of homopolymers and co-polymers having partially neutralized carboxylic acid groups are known. These contain between 3% and 20% of carboxylic acid residues of which less than 50 percent of the carboxylic acid groups are neutralized with mono-valent, divalent or trivalent cations. The prior art resins, known as Ionomers, are desirable in industry because they combine the utility of a thermoset polymer with the mobility and workability of the thermoplastic resin. Ionomers have lower densities than vinly or cellulosic plastics and because of their similarity to polyethylenes find use as protective films in the food packaging industry. Ethylene-methacrylic acid co-polymers are discussed in U.S. Pat. Nos. 3,266,272; 3,338,739; and in Belgium Pat. Nos. 674,595 and 600,397. Ethylene-sodium acrylate co-polymers are described in Netherlands Pat. No. 6,511,920. Many of the desirable properties of these polymers such as stress-crack resistance, transparency, grease and abrasion resistance, low permeability, high elongation, high tensile strength, and low modulus are attributed in part to a type of ionic bonding.
It has now been discovered that solid paints having effective gel properties necessary to provide dimensional stability can be prepared by cross-linking certain reactive polymers with "ion clusters" having polar molecule components. This type of ion bonding differs substantially from the solvent-free ionic bonding of the prior art compounds.